In the mid-1800s what issue divided the political parties? which two parties remained after the civil war?

Slavery divided the political parties in the mid-1800s. Even the small parties couldn't agree on how to handle it. The major parties had attempted to continue slavery despite losing and outlawing the slave trade. The other side had attempted to wipe it out and simply confine it. The Republican party would work to abolish slavery, while the Democratic Party would work to find ways to continue to oppress African Americans.